I. Field
The present disclosure relates generally to communication, and more specifically to techniques for operating a receiver in a communication system.
II. Background
The design of a high performance receiver is made challenging by various design considerations. For many applications, high receiver performance is required in order to meet system specifications and/or to achieve good data performance. Receiver performance may be characterized by various parameters such as dynamic range, linearity, and noise performance. Dynamic range refers to the range of received signal level that the receiver is expected to handle. Linearity refers to the ability to amplify a signal without generating a large amount of distortion. Noise performance refers to the amount of noise generated by the receiver.
A receiver is typically designed to meet all applicable system specifications. To support a wide dynamic range, which may be 90 decibels (dB) or more in a Code Division Multiple Access (CDMA) system, the receiver may have multiple discrete gain states, with each gain state providing a particular signal gain and linearity. A suitable gain state may be selected based on the received signal level and channel condition. The points at which to switch gain states may be defined such that the receiver can meet system specifications even with the worst-case operating conditions. The receiver may also be biased with a large amount of current in order to meet linearity requirements with the worst-case jammer conditions. Designing and operating the receiver for the worst-case jammer conditions may result in sub-optimal signal-to-noise ratio performance; and hence, lower data throughput, and higher power consumption in many operating environments.
There is therefore a need in the art for a receiver that can achieve good linearity performance and good signal-to-noise ratio (SNR) performance for better data throughput.